Zika virus blindfolds immune alarm cells

Dendritic cells are “sentinel” cells that alert the rest of the immune system when they detect viral infection. When Zika virus infects them, it shuts down interferon signaling, one route for mustering the antiviral troops. However, another antiviral pathway called RIG-I-like receptor (RLR) signaling is left intact and could be a target for immunity-boosting therapies, the researchers say.

Mehul Suthar, PhD in the lab with graduate students Kendra Quicke and James Bowen

Zika was known to disrupt interferon signaling, but Emory researchers have observed that it does so in ways that are distinct from other related flaviviruses, such as Dengue virus and West Nile virus. The findings give additional insight into how Zika virus is able to counter human immune defenses.

“This is the first demonstration of a flavivirus actively blocking translation of type I interferon, a critical set of innate immune signaling proteins,” says Mehul Suthar, PhD, assistant professor of pediatrics at Emory University School of Medicine and Emory Vaccine Center.

In addition, the researchers found that Zika blocks the phosphorylation of the immune regulatory proteins STAT1 and STAT2, which has not been previously reported.